Standing With the Assistance of a Tilt Table Improves Minute Ventilation in Chronic Critically Ill Patients Angela T. Chang, BPhty, Robert J. Boots, MBBS, MMedSci, FRACP, FJFICM, Paul W. Hodges, PhD, MedDr, Peter J. Thomas, BPhty, Jennifer D. Paratz, PhD, FACP ABSTRACT. Chang AT, Boots RJ, Hodges PW, Thomas PJ, Paratz JD. Standing with the assistance of a tilt table improves minute ventilation in chronic critically ill patients. Arch Phys Med Rehabil 2004;85:1972-6. Objective: To investigate the effect of standing with assis- tance of the tilt table on ventilatory parameters and arterial blood gases in intensive care patients. Design: Consecutive sample. Setting: Tertiary referral hospital. Participants: Fifteen adult patients who had been intubated and mechanically ventilated for more than 5 days (3 subjects successfully weaned, 12 subjects being weaned). Intervention: Passive tilting to 70° from the horizontal for 5 minutes using a tilt table. Main Outcome Measures: Minute ventilation (V ˙ E), tidal volume (V ˙ T), respiratory rate, and arterial partial pressure of oxygen (PaO 2 ) and carbon dioxide (PaCO 2 ). Results: Standing in the tilted position for 5 minutes pro- duced significant increases in V ˙ E (P.001) and produced both increases in respiratory rate (P.001) and VT (P=.016) com- pared with baseline levels. These changes were maintained during the tilt intervention and immediately posttilt. Twenty minutes after the tilt, there were no significant changes in ventilatory measures of V ˙ E,VT, or arterial blood gases PaO 2 and PaCO 2 compared with initial values. Conclusions: Standing for 5 minutes with assistance of a tilt table significantly increased ventilation in critical care patients during and immediately after the intervention. There were no improvements in gas exchange posttilt. Using a tilt table pro- vided an effective method to increase ventilation in the short term. Key Words: Intensive care; Physiotherapy; Rehabilitation. © 2004 by the American Congress of Rehabilitation Medi- cine and the American Academy of Physical Medicine and Rehabilitation S UBGROUPS OF PATIENTS admitted to intensive care are characterized by periods of prolonged mechanical ventila- tion. 1 These chronic critically ill patients account for 5.8% of intensive care unit (ICU) admissions but use 37% of ICU resources. 2 In addition to increased financial cost to the com- munity, prolonged ICU stays have been associated with greater mortality and reduced function. 3-5 Early rehabilitation is en- couraged in this population to optimize functional outcome after prolonged critical illness and ICU admission. 6 Physiother- apy (PT) rehabilitation techniques used in the management of this patient group include positioning, standing with the use of a tilt table, and mobilization. 7-9 Standing using the tilt table allows a patient to be passively tilted to varying angles to the horizontal and is hypothesized to increase ventilation, increase arousal, improve weight bearing of the lower limbs, and facilitate antigravity exercise of the limbs. 10 This technique is used as a precursor to standing when a patient has lower-limb weakness; it facilitates strengthening exercises of the upper and lower limbs. Despite use of tilting in this population, 7,9 its effects on respiration have not been investigated. Dean and Ross 11 in 1992 reported a case in which a woman admitted to intensive care after a motor vehicle crash was progressively tilted during her stay. Although Dean and Ross reported that her chest radiograph on the following day showed an increase in lung volumes, no measurements of ventilatory parameters or blood gases were recorded. In the clinical setting, tilting is often combined with other PT practices that are known to increase ventilation. 12 In the present study, our aim was to investigate the effect of the passive tilting component alone on short-term ventilatory parameters and gas exchange in a chronic critically ill population and to determine whether any changes were maintained after the intervention was completed. METHODS Participants A consecutive sample of 16 subjects who met the clinical criteria to begin using tilting as part of PT management was recruited over a period of 8 months. One recruited subject did not complete the study protocol because of clinical deteriora- tion; thus, a total of 15 subjects (11 men, 4 women), who were recruited from the ICU of a tertiary referral hospital, completed the study. The clinical criteria to commence tilting were sub- jects breathing spontaneously with supplemental oxygen (n=8) or with continuous positive airway pressure (CPAP) via a mechanical ventilator (n=7), 5 or more days on mechanical ventilation, an arterial oxygenation level above 70mmHg or oxygen saturation (SpO 2 ) greater than 90% in the absence of an arterial cannular (on a fraction of inspired oxygen [FIO 2 ] 0.4), and being deemed by the treating physiotherapist to be able to tolerate standing on a tilt table for 5 minutes by the treating physiotherapist. Subjects were excluded if they had frank bleeding, hemo- globin level less than 10g/dL, or platelet level less than 3010 3 /L; had an inotrope-dependent blood pressure; showed ischemic changes or arrhythmias on electrocardio- grams (ECGs), a suspected or confirmed deep vein thrombosis, or any other condition where weight bearing was contraindi- cated; body temperature above 37.8°C and/or resting heart rate From the Department of Physiotherapy, University of Queensland, St Lucia (Chang, Hodges); Intensive Care Facility, Royal Brisbane Hospital, Brisbane (Boots, Thomas); and Cardiopulmonary Research Centre, Alfred Hospital/La Trobe Univer- sity, Melbourne (Paratz), Australia. Supported by the Australian Physiotherapy Association (Dorothy Hopkins Award), the Australian Federation of University Women (Daphne Elliot Bursary), the National Health and Medical Research Council of Australia, and a Sir Robert Menzies Allied Health Scholarship. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Angela T. Chang, BPhty, Dept of Physiotherapy, University of Queensland, St Lucia, QLD 4072, Australia, e-mail: a.chang@shrs.uq.edu.au. 0003-9993/04/8512-8798$30.00/0 doi:10.1016/j.apmr.2004.03.024 1972 Arch Phys Med Rehabil Vol 85, December 2004